Heat exchanger

ABSTRACT

A heat exchanger for a motor vehicle may include a plurality of flat tubes for a first medium and two tube bottoms. The plurality of flat tubes may be aligned in a longitudinal direction and stacked spaced apart from one another in a stack direction to form a heat exchanger block. The plurality of flat tubes may each extend into the two tube bottoms. The heat exchanger may also include two guide plates which close the heat exchanger block such that a plurality of flow spaces for a second medium are delimited between the plurality of flat tubes. A plurality of depressions may be disposed in a longitudinal end region of one of the guide plates, may protrude into a respective flow space, and may follow a shape of the adjacent flat tubes area by area such that the at least one guide plate surrounds the plurality of flat tubes.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to German Patent Application No. DE 10 2018 214 944.5, filed on Sep. 3, 2018, the contents of which are hereby incorporated by reference in its entirety.

TECHNICAL FIELD

The invention relates to a heat exchanger for a motor vehicle.

BACKGROUND

Heat exchangers are already known from the prior art and are used in a motor vehicle to transfer heat between two media for example between a coolant and charge air. A generic heat exchanger thereby has a plurality of flat tubes, which are spaced apart from one another and which lead into the tube bottoms on the longitudinal end side. The charge air then flows through the flat tubes and the coolant flows into spaces of the spaced-apart flat tubes. The charge air and the coolant can exchange the heat via the wall of the flat tubes and the charge air can be cooled thereby. A heat exchanger is subject to a high thermal load, which may reduce the service life of the heat exchanger. Local thermal loads are usually compensated by an increase of the material thickness of the individual parts in the heat exchanger, which leads to a weight and cost increase. The coolant in the spaces can be guided in a targeted manner through guide plates arranged on the heat exchanger to the locations of the heat exchanger, which are under particularly high thermal stresses and they can be cooled. Disadvantageously, the material thicknesses of the individual parts can only be reduced to a limited extent even when utilizing a flow guide through the guide plates due to the partially very high thermal loads.

SUMMARY

It is thus the object of the invention to specify an improved or at least alternative embodiment for a heat exchanger of the generic type, in the case of which the described disadvantages are overcome.

This object is solved according to the invention by means of the subject matter of the independent claim(s). Advantageous embodiments are the subject matter of the dependent claim(s).

A heat exchanger is provided for a motor vehicle and has a plurality of flat tubes for a first medium and two tube bottoms. The flat tubes are thereby aligned in the longitudinal direction and are stacked spaced apart from one another in the stack direction to form a heat exchanger block. On the longitudinal end side, the flat tubes in each case lead into the tube bottoms, which are aligned transversely to the longitudinal direction. The heat exchanger further has two guide plates, which extend in the longitudinal direction and which close the heat exchanger block on both sides transversely to the stack direction, so that a plurality of flow spaces for a second medium are limited between the flat tubes. According to the invention, at least one of the guide plates has, at least on one side, a longitudinal end region, which connects to a longitudinal end of the guide plate in the longitudinal direction and which is arranged adjacently to the respective tube bottom. A plurality of depressions, which each protrude into the respective flow spaces between the adjacent flat tubes and which follow the shape of the respective adjacent flat tubes area by area, is thereby embodied in the at least one longitudinal end region. The respective guide plate surrounds the respective flat tubes at least area by area in the at least one longitudinal end region and thereby reinforces the flat tubes in the longitudinal end region.

In the at least one longitudinal end region of the respective guide plate, the flat tubes can be locally reinforced and the overall strength of the heat exchanger can thus be improved thereby. Partially opposing demands on the pressure change strength and the temperature change strength can additionally be met by means of the embodiment of the at least one longitudinal end region of the respective guide plate. On the one hand, in particular the stiffness of the heat exchanger and thus the temperature change strength of the heat exchanger can be increased and, on the other hand, the flexibility of the heat exchanger and thus the temperature change strength of the heat exchanger can be maintained. In the at least one longitudinal end region, the flat tubes are in particular effectively reinforced at the opening into the respective tube bottom, which is usually under high stresses, so that no further increase of the material thickness of the flat tubes is necessary. The weight and the costs of the heat exchanger can be reduced thereby.

It can advantageously be provided that the respective guide plate abuts against the respective flat tubes in a positive manner in the at least one longitudinal end region and is soldered to the flat tubes. The respective guide plate in the at least one longitudinal end region can be soldered to the flat tubes over a large area by means of the depressions, which surround the flat tubes area by area, whereby the overall strength of the heat exchanger can be improved.

In the case of a preferred embodiment of the heat exchanger, it is provided that the depressions are aligned in the longitudinal direction and extend to the longitudinal end of the respective guide plate, so that the respective guide plate is undulated at the respective longitudinal end. Due to this advantageous shape of the respective guide plate, the tolerances of the heat exchanger block and of the respective guide plate can be absorbed in an advantageous manner in response to the joining of the respective guide plate and of the heat exchanger block. If the flat tubes and the respective guide plate in the at least one longitudinal end region are soldered to one another, the flat tubes and the respective guide plate can move jointly in the at least one longitudinal end region in response to a placement process and can thus also be soldered to one another over a large area. The overall strength of the heat exchanger can be improved thereby.

It can advantageously be provided that a penetrating opening for the second medium is in each case formed in the respective depression. The penetrating opening thereby leads to the outside from the respective flow space between the adjacent flat tubes. The second medium can be supplied into the flow space through the respective opening or can be discharged from the flow space. Depending on the position of the respective opening in the respective depression, the second medium can be guided to the respective tube bottom of the heat exchanger—which is usually under the highest thermal stresses—and the latter can be cooled in a targeted manner. The heat transfer between the two media can further also be intensified by means of a targeted flow guide of the second medium in the respective flow space. The respective opening can be elongated, for example. The length of the respective opening can thereby be adapted to the flow guidance, which is to be attained, and to the intensity of the flow, which is to be attained, in the respective flow space, in order to optimize the heat transfer between the two media.

In the case of an advantageous embodiment of the heat exchanger it is provided that the respective guide plate has at least one side end region, which connects to a side end of the respective guide plate in the stack direction. The side end region is thereby rounded and surrounds the respective flat tube of the heat exchanger block, which is last in the stack direction, area by area in a positive manner. The heat exchanger block can be additional reinforced in this advantageous way and the overall strength of the heat exchanger can be increased thereby. The respective guide plate can additionally be folded over in the side end region, so that the respective side end of the guide plate is reinforced.

The heat exchanger can advantageously have two side plates, which are secured to the heat exchanger block and which extend in the longitudinal direction and which close the heat exchanger block in the stack direction. The respective side plate can have at least one plate end region, which connects to a plate end of the respective side plate transversely to the longitudinal direction. The plate end region can be rounded thereby and can surround the respective flat tube of the heat exchanger block, which is last in the stack direction, area by area in a positive manner. The heat exchanger block can be reinforced in this advantageous way and the overall strength of the heat exchanger can additionally be increased.

In the case of a further development of the heat exchanger it can be provided that the heat exchanger has at least one reinforcing rib, which is aligned in the longitudinal direction. The reinforcing rib can be secured to the respective guide plate on the one hand and to the respective side plate on the other hand and can reinforce the heat exchanger block in a corner region. In other words, the reinforcing rib can be secured in the side end region of the respective guide plate on the one hand and in the plate end region of the respective side plate on the other hand.

In summary, the flat tubes can be locally reinforced in the heat exchanger according to the invention and the overall strength of the heat exchanger can be increased thereby. The flexibility and thus the temperature change strength of the heat exchanger can in particular be maintained thereby, and the stiffness and thus the pressure change strength of the heat exchanger can nonetheless be increased. In contrast to a conventional heat exchanger, a further local increase of the material thickness of the flat tubes and of other individual parts can advantageously be forgone and the weight and cost increase resulting thereby can be avoided.

Further important features and advantages of the invention follow from the subclaims, from the drawings, and from the corresponding figure description on the basis of the drawings.

It goes without saying that the above-mentioned features and the features, which will be described below, cannot only be used in the respective specified combination, but also in other combinations or alone, without leaving the scope of the present invention.

Preferred exemplary embodiments of the invention are illustrated in the drawings and will be described in more detail in the description below, whereby identical reference numerals refer to identical or similar or functionally identical components.

BRIEF DESCRIPTION OF THE DRAWINGS

In each case schematically,

FIG. 1 shows a partial view of a heat exchanger according to the invention;

FIGS. 2 and 3 show views of a guide plate in the heat exchanger according to FIG. 1;

FIG. 4 shows a partial view of the guide plate at a heat exchanger block in the heat exchanger according to FIG. 1;

FIG. 5 shows a partial view of the guide plate in the heat exchanger according to FIG. 1 in a longitudinal end region;

FIGS. 6 and 7 show partial views of a heat exchanger, which is reinforced in a corner region;

FIGS. 8 to 10 show sectional views of a heat exchanger, which is alternatively reinforced in a corner region.

DETAILED DESCRIPTION

FIG. 1 shows a partial view of a heat exchanger 1 according to the invention for a motor vehicle. The heat exchanger 1 has a plurality of flat tubes 2 for a first medium, for example charge air, which are aligned in the longitudinal direction 3 and which are stacked at a distance from one another in the stack direction 4 to form a heat exchanger block 5. On the longitudinal end side, the flat tubes 2 in each case lead into the tube bottoms—not shown here—, which are aligned transversely to the longitudinal direction 3. The heat exchanger 1 has two guide plates 6—only one can be seen here—which extend in the longitudinal direction 3 and which close the heat exchanger block 5 on both sides transversely to the stack direction 4. The guide plates 6 thereby define a plurality of flow spaces 7 for a second medium—for example coolant—on both sides.

The guide plate 6 shown here has a longitudinal end region 8, which connects to a longitudinal end 9 of the guide plate 6 in the longitudinal direction 3. A plurality of depressions 10, which protrude into the respective flow spaces 7 between the adjacent flat tubes 2 and which follow corner radii 2 a of the respective adjacent flat tubes 2 area by area, are thereby embodied in the longitudinal end region 8. The guide plate 6 thus surround the respective flat tubes 2 at least area by area in the longitudinal end region 8 and reinforces them. As also shown in FIG. 4, the respective depressions 10 are aligned in the longitudinal direction 3 and extend to the longitudinal end 9 of the guide plate 6. The guide plate 6 is thereby undulated at the longitudinal end 9, and the tolerances of the heat exchanger block 5 and of the guide plate 6 can be absorbed in an advantageous manner in response to the soldering. The flat tubes 2 and the guide plate 6 can in particular move with one another in the longitudinal end region 8 in response to a placement process, and can thus be soldered to one another over a large area.

A penetrating opening 11 for the second medium, which leads from the respective flow space 7 to the outside, is in each case formed in the respective depression 10. The second medium can be supplied into the respective flow space 7 through the respective opening 11 or can be discharged from the respectively flow space 7. As also shown in FIG. 5, the respective opening 11 is elongated and, depending on the position of the respective opening 11, the second medium can be guided directly to the tube bottom—not shown here—and the latter can be cooled in a targeted manner. Due to the fact that the opening of the flat tubes 2 into the respective tube bottom is usually under the highest thermal stress, the thermal load on the heat exchanger block 5 can be reduced thereby and the service life of the heat exchanger 1 can be increased thereby. The length of the respective opening 11 can thereby be adapted to the flow guide, which is to be attained, and to the intensity of the flow, which is to be attained, in the respective flow space 7.

FIG. 2 and FIG. 3 show views of the guide plate 6 comprising the longitudinal end regions 8. The longitudinal end regions 8 are thereby embodied at the respective longitudinal ends 9 of the guide plate 6, so that the guide plate 6 can reinforce the flat tubes 2 at the respective tube bottoms on both sides. Depressions 10 comprising openings 11, which can form an inlet in the one longitudinal end region 8 and an outlet for the second medium into the respective flow spaces 7 in the other longitudinal end region 8, are thereby embodied in both longitudinal end regions 8.

FIG. 4 shows a partial view of the guide plate 6, which is secured to the flat tubes 2, in the longitudinal end region 8. As already described above, the depressions 10 protrude into the respective flow spaces 7 between the adjacent flat tubes 2 and follow the corner radii 2 a of the respective flat tubes 2 area by area. The flat tubes 2 are thereby reinforced particularly effectively. The respective depressions 10 thereby extend in the longitudinal direction 3 to the longitudinal end 9 of the guide plate 6, so that the tolerances of the heat exchanger block 5 and of the guide plate 6 are absorbed in an advantageous manner in response to the soldering.

FIG. 5 shows a partial view of the guide plate 6 in the heat exchanger 1. As already described above, the penetrating elongated openings 11 are embodied in the respective depressions 10. The second medium can thereby be guided to the opening of the flat tubes 2 into the respective tube bottom in a targeted manner and the opening can be cooled. The thermal load on the heat exchanger block 5 can be advantageously reduced thereby.

FIG. 6 and FIG. 7 show partial views of the heat exchanger 1, which is additionally reinforced in a corner region 12. The corner region 12 thereby extends in the longitudinal direction 3 and comprises a corner of the heat exchanger block 5. The guide plate 6 thereby has a side end region 13, which connects to a side end 14 of the guide plate 6 in the stack direction 4. The side end region 13 is rounded and folded over, so that the flat tube 2 of the heat exchanger block 5, which is last in the stack direction 4, is surrounded area by area. The heat exchanger block 5 is additionally reinforced thereby and the overall strength of the heat exchanger 1 is increased.

FIG. 8 shows a sectional view of the heat exchanger 1, which is reinforced in a further alternative manner in the corner region 12. The guide plate 6 is rounded in the side end region 13 here, but is not folded over. FIG. 9 shows a sectional view of the heat exchanger 1, which is reinforced in the corner region 12 in a further alternative manner. The heat exchanger 1 has a side plate 15 here, which is secured to the heat exchanger block 5. The side plate 15 extends in the longitudinal direction 3 and closes the heat exchanger block 5 in the stack direction 4. The side plate 15 has a plate end region 16, which connects to a plate end 17 of the respective side plate 15 transversely to the longitudinal direction 3. The plate end region 16 is rounded and surrounds the flat tube 2 of the heat exchanger block 5, which is last in the stack direction 4, area by area. The heat exchanger block 5 is thereby reinforced in the corner region 12 and the overall strength of the heat exchanger 1 is increased. FIG. 10 shows a sectional view of the heat exchanger 1, which is reinforced in the corner region 12 in a further alternative manner. The heat exchanger 1 has a reinforcing rib 18 here, which is aligned in the longitudinal direction 3 and which is secured to the guide plate 6 and to the side plate 15.

The flat tubes 2 can be reinforced in the heat exchanger 1 according to the invention and the overall strength of the heat exchanger 1 can be increased thereby. In contrast to a conventional heat exchanger, no further local increase of the material thickness of the flat tubes 2 has to be made thereby, so that a weight and cost increase are avoided. 

1. A heat exchanger for a motor vehicle, comprising: a plurality of flat tubes for a first medium and two tube bottoms; the plurality of flat tubes aligned in a longitudinal direction and stacked spaced apart from one another in a stack direction to form a heat exchanger blocks; on a longitudinal end side, the plurality of flat tubes each extend into the two tube bottoms, the two tube bottoms aligned transversely to the longitudinal direction; two guide plates extending in the longitudinal direction which close the heat exchanger block on both sides transversely to the stack direction such that a plurality of flow spaces for a second medium are delimited between the plurality of flat tubes; at least one guide plate of the two guide plates having, at least on one side, a longitudinal end region connected to a longitudinal end of the at least one guide plate in the longitudinal direction and arranged adjacent to a respective tube bottom of the two tube bottoms; and a plurality of depressions disposed in the longitudinal end region, the plurality of depressions each protruding into a respective flow space of the plurality of flow spaces disposed between adjacent flat tubes of the plurality of flat tubes, and each following a shape of the adjacent flat tubes area by area such that the at least one guide plate surrounds the plurality of flat tubes at least area by area in the longitudinal end region reinforcing the plurality of flat tubes in the longitudinal end region.
 2. The heat exchanger according to claim 1, wherein the at least one guide plate abuts against the plurality of flat tubes in a positive manner in the longitudinal end region and is soldered to the plurality of flat tubes.
 3. The heat exchanger according to claim 1, wherein the plurality of depressions are aligned in the longitudinal direction and extend to the longitudinal end of the at least one guide plate such that the the at least one guide plate is undulated at the longitudinal end.
 4. The heat exchanger according to claim 1, wherein a penetrating opening for the second medium is disposed in each of the plurality of depressions, and wherein the penetrating opening connects the respective flow space to an outside.
 5. The heat exchanger according to claim 4, wherein the penetrating opening is elongated.
 6. The heat exchanger according to claim 1, wherein: the at least one guide plate has at least one side end region connected to a side end of the at least one guide plate in the stack direction; and the side end region is rounded and surrounds a flat tube of the plurality of flat tubes disposed closest to the side end relative to the stack direction area by area in a positive manner.
 7. The heat exchanger according to claim 6, wherein the at least one guide plate is folded over in the side end region such that the side end of the guide plate is reinforced.
 8. The heat exchanger according to claim 1, further comprising two side plates secured to the heat exchanger block and extending in the longitudinal direction, wherein the two side plates close the heat exchanger block in the stack direction.
 9. The heat exchanger according to claim 8, wherein: the two side plates each have at least one plate end region, connected to a plate end of the respective side plate transversely to the longitudinal direction; and the at least one plate end region is rounded and surrounds a flat tube of the plurality of flat tubes disposed closest to the plate end of the respective side plate relative to the stack direction area by area in a positive manner.
 10. The heat exchanger according to claim 8, further comprising at least one reinforcing rib aligned in the longitudinal direction and secured to one of the two guide plates and to one of the two side plates reinforcing the heat exchanger block in a corner region.
 11. A heat exchanger for a motor vehicle, comprising: a plurality of flat tubes for conducting a first medium aligned with one another in a longitudinal direction and arranged spaced apart from one another in a stack direction to form a heat exchanger block; two tube bottoms disposed at opposing longitudinal ends of the plurality of flat tubes, the two tube bottoms aligned with one another transversely to the longitudinal direction; two guide plates extending in the longitudinal direction, the two guide plates arranged on opposing sides of the heat exchanger block closing the heat exchanger block transversely to the stack direction such that a plurality of flow spaces for conducting a second medium are delimited between the plurality of flat tubes; the two guide plates each having a longitudinal end region disposed at a longitudinal end of the respective guide plate, the two guide plates arranged such that the respective longitudinal end region is disposed adjacent to one of the two tube bottoms; wherein the two guide plates each include a plurality of depressions disposed in the longitudinal end region, the plurality of depressions each protruding into a corresponding flow space of the plurality of flow spaces; and wherein the plurality of depressions are each structured in a complimentary manner to adjacent flat tubes of the plurality of flat tubes defining the corresponding flow space such that the longitudinal end region of each of the two guide plates at least partially surrounds the plurality of flat tubes reinforcing the plurality of flat tubes.
 12. The heat exchanger according to claim 11, wherein the two guide plates abut against the plurality of flat tubes in a positive manner in the longitudinal end region.
 13. The heat exchanger according to claim 11, wherein the plurality of depressions extend along the respective guide plate in the longitudinal direction and are aligned within one another in the longitudinal direction such that the longitudinal end of the respective guide plate is undulated.
 14. The heat exchanger according to claim 11, wherein each of the plurality of depressions include a penetrating opening fluidically connecting the corresponding flow space to an outside.
 15. The heat exchanger according to claim 11, wherein each of the plurality of depressions include an elongated penetrating opening extending in the longitudinal direction and fluidically connecting the corresponding flow space to an outside.
 16. The heat exchanger according to claim 11, wherein: the two guide plates each have at least one side end region disposed at a side end of the respective guide plate in the stack direction; the side end region of the respective guide plate is rounded and wraps around a corner of an adjacent one of the plurality of flat tubes; and the corner of the adjacent one of the plurality of tubes defines a corner of the heat exchanger block.
 17. The heat exchanger according to claim 11, further comprising two side plates extending in the longitudinal direction and secured to the heat exchanger block such that the two side plates close the heat exchanger block in the stack direction.
 18. The heat exchanger according to claim 17, further comprising at least one reinforcing rib extending in the longitudinal direction between an associated guide plate of the two guide plates and an associated side plate of the two side plates, wherein the at least one reinforcing rib is secured to the associated guide plate and the associated side plate reinforcing a corner region of the heat exchanger block.
 19. A heat exchanger for a motor vehicle, comprising: a plurality of flat tubes for conducting a first medium aligned with one another in a longitudinal direction and arranged spaced apart from one another in a stack direction to form a heat exchanger block; two tube bottoms disposed at opposing longitudinal ends of the plurality of flat tubes, the two tube bottoms aligned with one another transversely to the longitudinal direction; two guide plates extending in the longitudinal direction, the two guide plates arranged on opposing sides of the heat exchanger block closing the heat exchanger block transversely to the stack direction such that a plurality of flow spaces for conducting a second medium are delimited between the plurality of flat tubes; at least one guide plate of the two guide plates has two longitudinal end regions disposed at opposing longitudinal ends of the at least one guide plate, the at least one guide plate arranged such that the two longitudinal end regions are each disposed adjacent to one of the two tube bottoms; wherein the at least one guide plate includes a plurality of depressions disposed in each of the two longitudinal end regions, the plurality of depressions each protruding into a corresponding flow space of the plurality of flow spaces; and wherein the plurality of depressions are each structured in a complimentary manner to adjacent flat tubes of the plurality of flat tubes defining the corresponding flow space such that the two longitudinal end regions each at least partially surrounds the plurality of flat tubes reinforcing the plurality of flat tubes.
 20. The heat exchanger according to claim 19, wherein the at least one guide plate includes both of the two guide plates. 